Display screen or portion thereof with transitional graphical user interface



FIG. 1 is the first image in a sequence for a display screen or portionthereof with transitional graphical user interface showing our newdesign;

FIG. 2 is the second image thereof; and,

FIG. 3 is the third image thereof.

The outermost broken lines, showing a display screen or portion thereof,form no part of the claimed design. The remaining broken lines, showingportions of the graphical user interface, form no part of the claimeddesign.

The appearance of the transitional image sequentially transitionsbetween the images shown in FIGS. 1-3. The process or period in whichone image transitions to another forms no part of the claimed design.

CLAIM The ornamental design for a display screen or portion there ofwith transitional graphical user interface, as shown and described.